MTN Melrose Arch refuses to cancel MTN contract or replace scratched device

On 15 July 2019 I took delivery of a laptop from MTN Melrose Arch. On arrival home I realised that the laptop had no CD rom which is what was confirmed to me that it had, and the laptop had two scratches on top. I returned to the store and was advised that the laptop would be replaced and that there was stock. When I returned to the store with the laptop, I was told that the laptop would have to be taken back to Lenovo and that I would have to wait for a replacement. When I protested, the store supervisor one Michael Rodrigues came out, refused to listen to my story and told me categorically that I will not get a replacement laptop as that was store policy. When I suggested to cancel the contract, he also refused saying that the terms and conditions that I signed only covered the mobile phones and not the laptops. How on earth could I have been made to sign a mobile device contract when I took delivery of a laptop. This man is rude, belligerent and simply refuses to listen to reason. All he does is shout and has little in the way of listening s****s. All I want is a replacement laptop and if not, I want to cancel this contract.